Currently, the environmental and behavioral processes that contribute to the emergence and maintenance of many health behaviors are not represented in system dynamics models. The lack of such models is a problem because until they are developed, there is no way to identify those levers of change that maximize healthful behavior while minimizing policy resistance. The objective of the current application is to develop and test a preliminary system dynamics model of the environment in tooth brushing frequency. Tooth brushing is an ideal health behavior to model because tooth brushing tends to co-occur with other health behaviors, such as seatbelt and helmet wearing. Thus, what we learn about tooth brushing is likely to generalize to those other health behaviors. Second, it displays policy-resistant tendencies. The central hypothesis of the application is that processes in the family and community affect tooth brushing behaviors in the child. This hypothesis is derived from health behavior theories. The rationale for examining these processes is that the family may be the most mutable and accessible target for preventive interventions. The central hypothesis will be tested in three specific aims. Aim 1 is to create a preliminary model of the dynamic relationships among individual-, family-, and community-level processes in tooth brushing frequency. It is hypothesized that tooth brushing frequency is determined by cultural processes manifested in the community and family. Aim 2 is to identify the levers that maximize tooth brushing while minimizing policy resistance. It is hypothesized that interventions should target the family and peer group. Aim 3 is to identify important, underspecified portions of the model. It is hypothesized that some portions of the model will be underspecified and will require data from studies that do not yet exist. The research proposed in this application is innovative because it utilizes system dynamics modeling. The contribution of the study is expected to be the identification of putative regulators that should be studied more intensively over time. This contribution is significant because it is the first step in a program of research that is expected to lead to the development of more accurate risk assessments for dental caries and interventions that increase tooth brushing frequency.